Beat-up mechanism for travelling-wave shedding looms



H. FEND 3,379,223

CHANISM FOR TRAVELLING-WAVE SHEDDING LOOMS April 23, 1968 BEAT-UP ME 2 Sheets-Sheet 1 Filed July 22, 1966 INVENTOR.

United States Patent 3,379,223 BEAT-UP MECHANISM FOR TRAVELLING-WAVE SHEDDING LOOMS Heinrich Fend, Uster, Zurich, Switzerland, assignor to Oerlikon-Buhrle Holding A.G., Zurich, Switzerland Filed July 22, 1966, Ser. No. 567,244 2 Claims. (Cl. 139-12) ABSTRACT OF THE DISCLOSURE In a beat-up mechanism for a progressive shedding loom comprising a plurality of sequentially operated reed elements each having a plurality of reed teeth, the active edges of the reed teeth on each reed element, and preferably also of adjacent reed elements as they are approaching the fell of the fabric, are situated on a straight line forming an angle with the fell. This line preferably is parallel to the portion of the weft thread which extends from the shuttle delivering it to the point where it is beaten up on the fell.

In travelling-wave shedding looms (occasionally called wave-weaving looms) a number of shuttles and sheds, as is well known, move in succession over the width of the fabric. Each shuttle inserts a weft thread into the accompanying shed, between the warp threads. The inserted weft thread is then beaten up against the fell of the fabric, immediately behind the shuttle.

The reed, which in conventional looms extends over the whole of the fabric width and which beats up a weft thread only after the lOng reed has entered the shed, consists, in the travelling-wave shedding loom, of a large number of successively arranged short reeds, each of which successively beats up a length of the weft thread. It would be desirable to replace each such reed by single beat-up element, approximately in the shape of a reed tooth that projects above the shed from between two neighboring warp threads. However, with fabrics of medium and close weaves the warp threads are so close togetherthat there would be no space for constructing sufficiently rigid reed teeth and for constructing an independently operated mounting for each tooth. This would be true even if several warp threads were located between neighboring reed teeth.

Preferably, therefore, a number of teeth forming a group of reed teeth are rigidly mounted in a row on a carrier to act as the reed.

In known travelling-wave shedding looms, the front edges (forming the beat-up faces) of the teeth of a rec lie along a line parallel to the beat-up edge of the fell.

Each shuttle, even when very close to the beat-up line at the fell, moves at least very nearly parallel to this line. On the other hand, the weft thread, which is contacted and held by the tooth nearest the shuttle of the reed last pushed against the fell, forms with the fell an acute angle opening in the direction of movement of the shuttle.

Thus, at the beginning of the beat-up movement only this tooth contacts the length of weft thread slanting towards the fell and which is to be beaten up.

ecause it originally slants, this length is longer than the portion of the fell against which it is beaten up. Since the weft thread is subjected only to a limited pull from the shuttle and since it is prevented by friction with the tooth and the warp threads from moving, in the direction of the shuttle, over the front edge of the tooth which holds it, the resistance of the weft thread to lateral movement is greater where it is in contact with the reed teeth than where it slants towards the fell. Thus, as

the teeth advance towards the fell, the excess of the length of weft thread is pushed back along the length of the fell portion against which it is to be beaten up, in a direction opposite to that of the shuttle and towards the previously beaten-up weft thread length.

After the beating up there is located between the two neighboring teeth of successive reeds located at the fell a portion of the weft thread somewhat longer than that between two successive teeth of the same reed. These 10- cations in the finished fabric appear striped, because the separation between warp threads is greater here than elsewhere in the fabric.

The appearance of such stripes also arises from the step-by-step progression of the beating up, which produces an uneven tension in the warp threads.

The object of the invention is to prevent the appearance of these stripes and to improve the uniformity of the Weave fabric over the entire width of the fabric, regardless of the fact that the weft is beaten up by a series of reeds rather than by a single reed.

An embodiment of the invention will now be described in detail, with reference to the accompanying drawings, wherein:

FIGURE 1 is a side view of a portion of the weftthread inserting and beat-up mechanism;

FIGURE 2 is a schematic top view taken along line II-Il of FIGURE 1; and

FIGURE 3 is a view on expanded scale, also taken along line IIII of FIGURE 1, of three groups of reed teeth shown at the moment that a weft thread portion is beaten up.

Referring to FIGURE 1, there is illustrated a part of a weft-thread inserting and beat-up mechanism. A group of warp threads 1 from a warp beam (not shown) pass through shafts of healds (not shown), which spread out the warp threads to form sheds 2 that move across the width of the finished fabric. The threads of a shed extend to the beat-up line at the fell 3 of the fabric 6. To preserve the simplicity of the drawings, only a few of the warp threads are shown at FIGURES 2, 3. A weft thread 4 is put into each shed 2 by a shuttle 5 and then is beat up at the fell 3 by means to be explained. Movement of the healds changes the position of the warp threads 1 (between which the weft thread 4 is inserted), whereby the weft thread is woven with the fabric 6 and now forms the fell.

This weaving of the weft is effected simultaneously by a plurality of spaced shuttles 5 moving along the fabric width.

The weft-thread inserting and beat-up mechanism incorporates a large number of slides 7, which move in parallel grooves (not shown) in the frame of the travellingwave shedding loom. A drive (not shown), powered by the main drive shaft of the loom, moves each slide 7 back and forth. This movement is so effected that at any given moment the position of successive slides 7 is displaced, whereby the sum of corresponding points on the slides will describe a curve, or travelling wave, which advances in the direction of the arrow 8, FIG. 2, transversely to the warp threads 1. The shuttles 5 move in the troughs of the wave, also transversely to the warp threads. The curve comprises portions that are similar to a sine wave, in the troughs of which the shuttles 5 are located, and portions that are straight and composed of slides 7 that are located in their forward position, ready for movement in the return direction. There are as many portions similar to sine waves distributed over the width of the fabric woven as there are shuttles. At FIGURE 2 there is shown of the curve only a single trough (with shuttle) and a part of one straight portion formed by two of the slides in their forward position.

Each slide 7 has a vertical connecting member 9 which, during the to-and-fro movement of the slide, remains bclow the lower respective warp threads 1 defining the lower sheet of the shed. A member 9 is laterally guided by the members 9 of the neighboring slides 7. A group of parallel teeth 11, which, for example, may be eight in number, project from each member 9, forming one reed 12. The number and separation of the teeth 11 are so chosen in dependence on the fabric to be woven, that each warp thread 1 (which, according to the position of the shuttle, will shortly define the upper or lower extremity of the shed 2), or small group of warp threads, is guided on each side by a tooth 11, FIGURE 2. Each tooth, for every position of its slide 7, projects from. between two neighboring. warp threads 1 above the plane of the warp threads defining the upper limit of the respective shed 2.

Each group of teeth 11 of a slide 7 incorporates a head 13 that connects together the teeth of a reed and ensures the correct separation between them. Each head 13 has two fiat parallel lateral faces, and is sufficiently wide that each face is in sliding contact with the opposed face of the neighboring head. These faces are sufficiently long in the direction of movement of the slides 7, so that neighboring faces are always in contact for all possible relative positions of consecutive slides.

The beat-up faces formed by the front edges 14 of the teeth 11 of a reed 12 are successively set back in the direction of movement of the shuttles 5, so as to form a plane that defines with the heat-up line at the fell 3 approximately the same angle or (FIG. 2) as does the weft thread 4 running from the shuttle 5 towards the beating-up position.

The movement of the slides 7 is so controlled that, as several neighboring slides approach their forward position, the front edges 14- of the teeth 11 of the several reeds 12 lie in a common plane forming with the beat-up line at the fell approximately the angle a. It is also here that the shape of the curve departs from its sine-wave form. As illustrated at FIGURE 2, the front edges 14 of the teeth of reed 12b of the slide 7 most recently brought to a stop at its forward position, as well as those of the next two slides approaching their forward position, lie in the said common plane. The invention is not limited to three reeds 12 defining a common plane. The control can be such that two reeds or more than three reeds are involved.

A guiding and driving fork 15 for the shuttles 5 is mounted on each member 9 of a slide 7 in front of the reed 12. The to-and-fro movement of a slide 7 causes its fork 15, during the forward movement of the slide, periodically to emerge from the shed 2 between two warp threads 1 and to move below the beat-up edge at the fell 3 until the reed 12 of that slide has completed the beating up of the weft thread 4. Subsequently, the fork 15 returns between these warp threads into the shed 2 formed in the meantime by the heald movement, where it helps to cause and control the movement of a shuttle S.

The forks 15, of course, define the same curve as do the slides 7. Each shuttle is provided with a rib 17, trapezoidal in cross section, that engages a recess 16 of a fork 15. A shuttle engages the recesses 16 of the forks 15 of those slides 7 that constitute at any given moment the trough of a sine-wave portion of the curve. A shuttle occupies approximately a half period of a sine wave. The forward movement (appearing in FIGURE 2 as downward) of the slides forming the right half of the trough urges the shuttle 5 to the left, in the arrow direction, while the opposite movement of the slides forming the left half of the trough permits the shuttle to move. The shuttle moves in a straight line parallel to the fell 3. The flat underside of a shuttle slides on the upper horizontal faces of the front teeth of the forks 15, FIG. 2.

Each moving shuttle, which is accompanied by a surrounding shed 2, continuously introduces the weft thread 4 into the shed. The weft thread is then led to the fell by the reeds 12 of those slides 7 of which the forks 15 have just been disengaged from the rib 17, where it is beaten up. Since a shuttle moves along a line spaced from the beat-up line and the beating up occurs behind each shuttle, the portion of the weft thread to be beaten up forms an acute angle or with the beat-up edge of the fell 3. As already remarked, the plane in which the front edges 14 of the teeth 11 of a reed and the plane in which the front edges of the three of reeds 12b, 12c, 12d lie also forms approximately the angle or with the fell 3. Because the weft thread 4 slants, that portion which is to be beaten up is somewhat longer than the portion of the fell 3 against which the thread is beaten.

Since the plane of the front edges 14 of the reeds 12b, 12c, 12d is parallel or nearly parallel to the portion of the weft thread to be beaten up, the front edges touch the weft thread virtually simultaneously. This prevents during the beating up any lateral movement of the weft thread or at least reduces it to that portion which is to be beaten up that ties farthest from the fell 3 (in the region of reed teeth 12c, 12d).

The front edges 14 touching the weft thread move the thread parallel to itself and against the weft thread previously inserted and forming the fell 3 or, depending on the weave pattern, against the crossed warp threads.

After the weft thread 4 has been pushed against the warp threads 1 by all of the teeth 11 of a reed 12 and after the most advanced of these teeth have also temporarily pushed somewhat forward the previously inserted weft thread forming the previous fell 3, the slide of that reed is stopped. This is the case with the slide of reed 12b at the moment illustrated in FIGURE 2. Reed 12a, and those of the other slides (not shown) to theright, remain stopped in their forward position to hold in place the weft thread 4 forming the new fell 3, until the warp threads I. are further woven about it. Generally, it is the most advanced teeth 11 of a reed 12 that holds the weft thread in place.

In the meantime, the slides of reeds 12c, 12d move forward at the same speed until they are successively brought to a stop in their forward position. At the same time, the slide for reed He moves forward faster than do the slides of reeds 12c, 12d, until the front edge 14- of its teeth 11 come to lie in the same plane as do those of reeds 12c, 12d. The slide 7 of reed 122 now moves forward at the same speed as those of reed teeth 12c, 12d.

If the front edges 14 were to lie in a plane parallel to the fell 3, as is the case with the prior art, the tooth 11 lying nearest the shuttle 5 would contact the weft thread 4 first. The portion of the weft thread located between the tooth and that portion already beaten up located after the reed 12 cannot be moved over this tooth towards the shuttle, but rather is pressed, in a direction opposite to that of the shuttle movement, against the fell 3 by the remaining teeth of the reed. This portion, which is longer than the width of the reed 12, because originally it slanted, would be pushed back against the fell in the space located between the neighboring end teeth of reed 12 which is now beating up and that of the reed 12 which has just finished beating up. In the finished fabric the warp threads would be spaced farther apart in this space than over the width of the reed.

The invention avoids this shortcoming of the prior art by stepping the positions of the teeth 11 of each reed. Thus, the weft thread 4 is always beaten up in the direction of shuttle advance subsequent to a position in which it is held by another tooth of the same or of the pre vious reed.

The mechanism for obtaining the desired movement of the slides 7 is disclosed in United States Patent No. 3,255,782, granted July 14, 1966, in the name of the present inventor.

I claim:

1. Weft thread beat-up mechanism on travelling-wave looms, comprising reed portions arranged beside each other in the direction of movement of the shuttles and individually movable towards the fell of the fabric and away from it, each said reed portion comprising a plurality of rigidly interconnected reed teeth, said reed portions having their corresponding points at any time forming a curve which in the vicinity of the fell of the fabric has a substantially straight portion parallel to the portion of the Weft thread which extends from the shuttle to said fell of the fabric, the front edges of the individual reed teeth of each reed portion being stepped back away from the tell of the fabric as one proceeds in the direction of movement of the shuttles.

2. Weft thread beat-up mechanism as set forth in claim 1, wherein the front edges of the reed teeth of each reed portion lie in a plane Which is parallel to said substantially straight portion of said curve formed by the corresponding points of said reed portions.

References Cited UNITED STATES PATENTS 2/1903 Salisbury 139-12 4/1910 Salisbury 139-12 2/1966 Fend 139-12 3/1966 Fend 139-12 6/1966 Pond 13912 FOREIGN PATENTS 6/1964 France.

ROBERT R MACKEY, Acting Priinmy Examiner.

I. KEE CHI, Assislant Examiner. 

